Patent GB-190806222-A (GB)
Title: Improvements in Steam Engines or Steam Power Motors.
Inventor: BICKERTON HERBERT LAURENCE
Filed: 1908-03-20
Granted: 1908-12-10
Abstract: 6222. Bickerton, H. L. March 20. Hot-air engines. - Reciprocating engines and turbines are worked by a mixture of compressed air and highly superheated steam. The addition of air produces internal cooling and permits the steam to be superheated to a temperature, say considerably over 300‹ C., at which it could not be safely employed alone. The steam and air are preferably in such proportions that the mixture is at a pressure equal to that in the boiler, an effective proportion being two by weight of compressed air and one of superheated steam. The mixture may be produced in the engine cylinders, or may be supplied from receivers which may be fitted to existing engines. Three types of engine are described. (1) A double-acting single-expension twocylinder engine, (2) a compound engine with two pairs of tandem cylinders, and (3) a turbine. (1) This engine with cranks at 180 degrees is shown diagrammatically in Fig. 1, in which the clearance spaces are shown at M. Assuming the left-hand piston to be at the top of its stroke with compressed air above it in the space M, the cycle for the upper end of the cylinder would be (a) admission of steam driving the piston down, (b) exhaust, (c) suction of atmospheric air, and (d) compression of this air. The cycle in the lower end of the cylinder would commence with compression of air, that above the right-hand piston with exhaust, and that below the right-hand piston with suction of air, the sequence of operations being the same in both ends of each cylinder. A sectional view of this type of engine is shown in Fig. 4. Steam is admitted by a pipe 7 and balanced valves 8, worked in pairs by cams 9 on a shaft 11 driven at half speed by a crank-shaft through a chain 17 to gear-wheels 13, 14, or entirely by wheels and shafts. The steam valve-gear consists of the cam 9 on the shaft 11 which works corresponding valves in the two cylinders through levers loaded by springs. The exhaust and suction valve-gear is shown in Fig. 10, except that the grid slide valves Ev loaded by springs 26 are placed on the underside of the cylinder, and the levers 23, 24 are carried down between the cylinders. The exhaust cams 25, Fig. 4, are placed on the shaft 11. (2) This engine with cranks at 180 degrees is shown diagrammatically in Fig. 3. Assuming the left-hand piston to be at the top of its stroke with compressed air above it, the cycle for the space I would be : (a) admission of steam, driving the piston down, (b) exhaust of half-expanded steam to the space II, (c) suction of air compressed to half its ultimate pressure in the space VIII, and (d) compression of this halfcompressed air. Similar cycles occur in the remaining high-pressure spaces III, V, VII. For the space IV, the cycle would be : (a) suction of atmospheric air, (b) compression of this air to half its ultimate pressure, (c) admission of halfexpanded steam from the space VII, and (d) exhaust. Similar cycles occur in the remaining low-pressure spaces II, VI, VIII. Steam is admitted by the valves Sv, and the flow through the connecting-pipes is controlled by valves Suction and exhaust valves are marked Ev. The engine is shown in Fig. 7, in which the low-pressure cylinders 27, 28 are surmounted by the highpressure cylinders 5, 6. Steam is admitted by the pipes 7 and valves 8, these valves being operated by cams 9 on the shaft 11, as described above for the first type of engine. The shaft 11 is driven at half speed through the chain 17, shaft 12, and wheels 13, 14. The exhaust and suction valves, and gear are shown in Fig. 10, and are the same as described above. The steam and air valves 29 are similar in construction and method of working to the valves 8, and are actuated by cams 30. The half-compressed air valves 31 are similar to the exhaust valves and are actuated by cams 32. The half-expanded steam and air is conducted from the upper ends of the cylinders by the pipes 33, 34, and from the lower ends by the pipes 35, 36, upon all of which valves 29 are placed. The half-compressed air-pipes are shown at 37. (3) A Parson's or other steam turbine is shown in Figs. 12 and 17. The end plate 41 of the turbine 38 has cast with it a receiver consisting of chambers 39, 40, to which superheated steam and compressed air are admitted by pipes 7, 53, the air being supplied by a blower 52 preferably of the type described in Specification No. 28,144, A.D. 1903, [Abridgment Class Rotary engines &c]. The mixture of air and steam is admitted to the turbine from the chambers 39, 40 alternately by valves 60, actuated by the cam 61 on the shaft 11 through rods 62, 55 and levers 21, 22. The grid valve 48 admitting compressed air alternately to the chambers 39, 40, and the steam valves 8 are actuated by cams on the shaft 11. Where the receivers are fitted to existing reciprocating engines, the air is compressed by a pump worked direct from the engine.